NONEQUILIBRIUM POINT-DEFECTS AND DIFFUSION IN SILICON

Many surface and bulk processes generate or consume point defects in crystalline silicon. Some such processes that commonly occur in silicon device fabrications include impurity/dopant diffusion, thermal oxidation, thermal nitridation, silicidation, plasma treatment, ion implantation and oxygen precipitation. These processes can cause the concentrations of point defects to depart from their thermal equilibrium values. Nonequilibrium point defects can profoundly affect dopant diffusion. They may also engender extended defects, such as stacking faults and dislocations. Understanding of the causes and effects of nonequilibrium point defects is a prerequisite for the prediction and control of dopant diffusion in the fabrication of modern submicron devices. This report reviews technologically important processes that cause nonequilibrium point defects in silicon, and our current understanding of them.